The present invention relates to a projection electrode for use in a semiconductor device, its components, manufacturing apparatus, testing apparatus, and so on and a method for forming the same and apparatus for testing an electronic component.
A projection electrode on a wiring board's electrode used for a semiconductor chip, etc., and a method for forming the same are conventionally known, for example, in Jpn. Pat. Appln. KOKAI No. 5-55306.
This projection electrode 400 is formed as shown in FIG. 15. That is, line-like wirings 200 comprised of a wiring metal material of various kinds of metals such as Au, Ag or Cu or alloys thereof are pattern-formed on an insulating film 100 such as a polyimide resin film. Then, an encapsulating resin 300 having an electrical insulating property, such as a polyester series resin, is coated over the insulating film 100 and the portions of the encapsulating resin 300 situated over the line-like wirings 200 are eliminated by a machine process, a laser beam, etc., to provide line-like wiring exposed portions 700. Finally, a projection electrode 400 is formed by an electroplating method, etc., on the surface of the line-like wiring exposed portions 700 to complete a wiring board 500.
According to this projection electrode and its forming method, it is not necessary to make holes in a base substrate (insulating film 100) and fill an electroconductive substance in the hole. As a result, an added strength can be achieved on the whole wiring board 500 and the thickness, material, etc., of the insulating film 100 can be freely selected in accordance with an intended object. Further, since the projection electrode 400 is formed on the line-like wiring 200, it is easier to recognize the electrode position and circuit pattern configuration, and a semiconductor chip can be easily mounted on the wiring board 500, so that it is possible to achieve an increased production of the semiconductor device.
Also known is a testing apparatus for testing the circuit of a semiconductor device of a bare chip and chip sized package (CSP) by setting the thus formed projection electrode on the corresponding electrode of the testing board comprised of a printed circuit board. According to the testing apparatus for testing this electric component, a socket is used to allow this projection electrode to be connected to the corresponding electrode on the CSP for example and, after the CSP has been mounted on a CSP mount section provided at the socket, the socket is set at a predetermined position on the testing board with the projection electrodes formed thereon to connect the electrode of the CSP to the corresponding projection electrode, and a voltage is applied to the circuit to check the circuit for an operation.
However, the projection electrode 400 formed by the above-mentioned projection electrode method is comprised of a so-called ball bump having a hemispherical surface. In the case where this projection electrode 400 is used on the electric circuit testing board for testing many CSPs in a repeated fashion, a soldering of the electrode material of the CSP electrode is transferred or deposited on its contacting surface of the projection electrode 400 through the repeated contacting of it with the CSP electrode as a contacting object and acts as a resistance and therein arises the problem that, due to the worn state of the projection electrode 400, an electrical connection is noticeably lowered between the testing board-side wiring and the CSP-side circuit wiring. Further, one ball bump-like projection electrode is formed on one basic wiring and, when there occurs, for example, a warp or waviness on the testing board and CSP per se, a non-contacting portion occurs due to a gap between the testing board-side wiring and the CSP electrode, making it impossible to obtain an electric connection therebetween, and hence to perform thorough circuit checking.